import React, { Component } from 'react'
import './index.css'
export default class Footer extends Component {

  handleCheckAll=(event)=>{
    this.props.checkAllTodo(event.target.checked)
  }
  handleClearAll = ()=> {
    this.props.clearAllDone()
  }

  render() {
    const {todos} = this.props
    //已经完成的
    const doneCount = todos.reduce((pre,todo)=>{
      return pre+(todo.done ? 1 : 0)
    },0)
    const total = todos.length
    return (
   <div className="todo-footer">
      <label>
        <input type="checkbox" checked={doneCount===total && total!= 0  ? true :false} onChange={this.handleCheckAll} />
      </label>
      <span>
        <span>已完成{doneCount}</span> / 全部{total}
      </span>
      <button className="btn btn-danger" onClick={this.handleClearAll}>清除已完成任务</button>
    </div>
    )
  }
}
